Family Systems and Family Development: The Selection of Analytical Units: Alexander von Eye and Kurt Kreppner
A system may be defined as an entity or a whole of material or abstract elements that has a structure (cf. Angyal, 1969; Klaus & Liebscher, 1979). Anything relevant to a particular research question may be used as an element. Examples of material elements include individuals, texts, and pictures. Examples of abstract elements include ideas, theorems, and processes. Depending on the research question, a particular subset of attributes ofthese elements is investigated. For instance, in memory research recall rates may be of interest, whereas physical attractiveness of subjects may be irrelevant. The list of attributes under study in an investigation contains the elements of the object system (Cavallo, 1979). The study of a system's elements as "objects" allows the researcher to select from a multitude of possible aspects, depending on the weights of the objects in a given system.